officers closed two sublanes near baltimore for the stop. official says they got a call about 7:00 this morning ha a passenger was in possession of a dangerous substance. his flight was already airborne on the way to dallas. authorities turned it around and armed officers pulled that passengers christopher shell from his seat for questioning. it became clear to investigators that shell may have been the victim of a prank on his 29th birthday. >> that this was a hoax, and a pretty nasty trick was played on a passenger, and it resulted in really a threat to all the passengers. incredibly foolish and irresponsible thing to do. at the bottom line, it's criminal. >> the hox will cost tens of thousands, not to mention the disruption in the lives of dozens of passengers. >>> airne seats are about to get even tighter. united airlines is installing what it calls slim-line seats to the airline can pack in a few more passengers. they've by 17 inches long, an inch shorter, slimmer backrests, but the airline says legroom is supposed to stay the same. at